I arranged my army like this, with the purpose being to form a shield wall with the Liberators to protect the Judicators and lock the enemy in place, while my archers would thin down the ranks as they approached:
My Lord Castellant used his lantern to strengthen the front line while I was planning to use the Venator to go round sniping Heroes.

The actual battle ended very quickly, as my opponent surrendered after one and a half battlerounds. He had lost 26 models. I'd lost 2. Personally I put it down to unlucky dice rolls and tactics that consisted of run into the middle and start hitting things.

The point of all of this is that my opponent wanted to know what tactics he could of used to stand a better chance of winning. He put it down to a lack of shooting, but I think there still would be ways to better combat me. He now has the Start Collecting Daemons of Khorne if that would change your list choices.

I arranged my army like this, with the purpose being to form a shield wall with the Liberators to protect the Judicators and lock the enemy in place, while my archers would thin down the ranks as they approached:View attachment 41132
My Lord Castellant used his lantern to strengthen the front line while I was planning to use the Venator to go round sniping Heroes.

The actual battle ended very quickly, as my opponent surrendered after one and a half battlerounds. He had lost 26 models. I'd lost 2. Personally I put it down to unlucky dice rolls and tactics that consisted of run into the middle and start hitting things.

The point of all of this is that my opponent wanted to know what tactics he could of used to stand a better chance of winning. He put it down to a lack of shooting, but I think there still would be ways to better combat me. He now has the Start Collecting Daemons of Khorne if that would change your list choices.

Aside from him just getting more stuff so he can make an actualy coherent army there isn't much he can do. The Khorne army in the starter set is well... rather pathetic... Ranged attacks can decimate the army easily before it ever gets in melee combat and on top of that it most of it can only barely scratch your liberators, let alone kill em. Doubly so with that latern guy healing em...

Glaring weaknesses in that starterbox:

1 Korgorath can't reliably kill anything so it won't heal. You either need multiple korgorath in a unit, or you need to be facing cannonfodder so it can actually get kills and heal.

Blood reavers are squishy as hell, with only 20 they can be annihilated in a single turn by your ranged attacks alone...

Blood warriors are decent, but there's only 5... (it'd been much better if it had been say 10 warriors and 10 reavers in that box...)

Bloodsecrator seems great at first glance. But with half your army annihilated before long it just doesn't get to do much....

Bloodstoker just doesn't add much to the list, more warriors or reavers would've been more usefull..

Lord of Khorne. decent but basicly the only unit in that box that actually carries its own weight. And well 1 unit doesn't make an army...

Obvious advantages you have:

Ranged attacks which can easily take out half his army before he even gets to you

Mortal wounds or healing prayer

re-rollable healing save nonsense on your frontline liberators

Basicly you can easily annihilate most of his army from range while even in melee he'l have great difficulty even scratching you. And no that's not just bad rolls, the khorne army in that starter set is just that stupidly uneffective of an army...

If you want to make things easier on him do the following

Limit the ranged attacks you bring, he simply doesn't have the numbers or speed to advance under a hail of fire.

Don't bring stuff with particularly good saves, most his stuff will struggle to hurt unbuffed liberators, let alone ones buffed with that lantern...